Solid milk is proposed which is compressively molded from a predetermined amount of powder milk so as to enable preparation of desired milk that is easily portable and eliminates measurement at the time of going out (Patent Document 1: WO2006/004190). A rotary tableting machine used for fabricating tablet medicines and the like are disclosed as a molding machine for compressively molding the solid milk (Patent Document 2: Japanese Patent Laid-open No. Hei 6-218028, Patent Document 3: Japanese Patent Laid-open No. 2000-95674, etc.)
Such tableting machines are used for compressively molding tablet medicines, tablet-like foods, bath agents, agrichemical, and other medical agents and suitably configured to firmly compress and mold powder into relatively hard compacts. Thus, they are not suitable for compressively molding the solid milk mentioned above.
More specifically, solid milk molded from powder milk is required to be compressively molded at a low compression force so as to have a porosity of 30% or more so that it is satisfactorily and quickly dissolved by being poured in warm water. In addition, the solid milk needs practical shape-retaining performance without damage while being transported or taken along.
In the present specification, “porosity” means the ratio of void volume to the bulk volume of powder (see, Edited by Koichiro Miyajima, “Development of Drug Medicine”, Vol. 15, Hirokawa Publishing Company, page 240, 1989).
If the tableting machines mentioned above perform compression molding at a lower compression force, the molding speed must be reduced because compacts may be damaged at the time of being discharged and collected from the molding machine after compressively molded. This significantly reduces fabrication efficiency. In addition, since the tableting machines do not essentially aim to perform compression molding at such a low compression force, it is extremely difficult to adjust porosity. That is to say, it is difficult to stably mold solid milk having a porosity of as large as 30% or more. These tableting machines fabricate compacts as below. A lower punch is inserted from below into a hole-like die perforated upward and downward and molding powder is poured in the die and is tamped down with upper and lower punches. Usually the compacts are lifted up with the lower punch and discharged from the upper side of the die. Then the compacts are collected in such a manner as to be raked down from a plate formed with the die. Thus, compacts that are molded at a low compression force so as to increase porosity are likely to disadvantageously crumble at the time of the collection.
[Patent Document 1]                WO 2006/004190        
[Patent Document 2]                Japanese Patent Laid-open No. Hei 6-218028        
[Patent Document 3]                Japanese Patent Laid-open No. 2000-95674        